在英语中，常用的介词包括：in, on, at, by, with, for, to, of, as, like, after, before, since, until, during, between, among, near, next, past, behind, in front of, above, below, under, over, across, through, into, out of, along, around, up, down, back, off, out, in, on, here, there, now, then, soon, later, yesterday, tomorrow, today, tonight, this morning/afternoon/evening, every day/week/month/year, once a week/month/year等。

这些介词在句子中主要用来表示时间、地点、方向、原因等关系。例如：“I go to school by bus.”（我乘公交车去上学）中的“by”表示方式；“I will meet you at the park.”（我会在公园见你）中的“at”表示地点。要学好这些介词，可以通过多听、多说、多读、多写来熟悉它们的用法。同时，可以借助一些记忆技巧，如制作卡片、编故事或进行角色扮演游戏等，帮助巩固记忆。